Patent GB-944226-A (GB)
Title: Improvements in or relating to devices for use in the production of printing master sheets
IPC: G03D9/00
Filed: 1960-12-15
Abstract: 944,226. Photographic processing apparatus. W. RITZERFELD, and G. RITZERFELD. Dec. 15, 1960 [Dec. 24, 1959; April 5, 1960], No. 43170/60. Heading G2A. A device for use in the production of printing master sheets from light sensitive sheets having a hardenable gelatinous coloid layer comprises a container for a processing liquid and a guide channel adapted for guiding a light sensitive sheet through the container for processing therein, a pair of feed rollers for the sheet being provided at the entry to the channel and another pair of feed rollers at the exit therefrom, means being provided for guiding and feeding a transfer sheet to the pair of rollers at the exit from the channel in such manner as to enable the transfer sheet, after passage of the light sensitive sheet through the container, to be pressed against the light sensitive sheet by the pair of rollers at the exit of the guide channel above, or together with a further pair of rollers subsequent thereto in the direction of movement of the light sensitive sheet. A first embodiment (Fig. 1) is provided with an entry table 32 for an exposed silver halide sheet 40 and entry guides 33, 34 for a transfer sheet 41. Entry feed roller 18 is continually driven from a motor 96 by a belt 98 but entry feed roller 17 pivotally mounted on an arm 111 is idle. On bring- ing the two rollers together under spring loading, the sheets are respectively fed through the channels formed by pairs of guides 19, 20 and 49, 50. The lower channel leads through a container 21 of developer for processing the exposed silver halide sheet. The two sheets are pressed together and dried by roller pairs 23, 24 and 25, 26-23 and 25 of which are heated. The two sheets are manually separated as they emerge through exit channel 29, 30, the gelatine layer adhering to the transfer sheet in the unexposed areas and ink adhering to the hardened gelatine in the image areas. This first embodiment is provided with two further containers 6, 14 whereby an alternative process may be performed. In this case the developer is contained in bath 6 and container 21 comprises an acidifying/oxidising bath. Container 14 with its agitators 12, 13 and thermostatic control comprises a washing bath. An exposed silver halide sheet fed in at A over a feed table, will then be passed through the baths 6, 14, 21 in succession by means of pairs of feed rollers 2 and 3, 8 and 9, 17 and 18, 23 and 24, 25 and 26 and by means of guide members 4, 5, 10, 11, 19 and 20. Rollers 3, 8, 9, 18 and 23 are driven through belt and pulley drives from the motor 96. The roller 9 has a serrated surface so as not to provide a squeegee action. All of the containers 6, 14 and 21 may be lifted out after a cover 35 has been pivoted upwards about a pivot 31. In a modification of this first embodiment (Fig. 2, not shown), the upper channel, for the transfer sheet, comprises water tight guide plates which actually dip into the bath 21 and the rollers 25, 26 are replaced by a heated exit channel. In a second embodiment (Figs. 3 and 4) the bath 21 is accommodated in a separate housing 61 which is releasably attached to a main housing 57 by latches 81 and may be replaced,by a further bath-containing housing 86 (Fig. 4). Drive is transmitted between the housings through a toothed wheel 123. Further, in this embodiment, the transfer sheet is provided with a separate feed table 68 adjacent exit pair of rollers 72, 23, the roller 72 being pivotally mounted and under the control of a sensing device (Fig. 5, not show ) for sensing the approach of a developed light sensitive sheet towards the rollers 72, 23. By the use of the three housings in different combinations, the two processes described above can be performed by this embodiment also. A different process may be performed in a third embodiment (Fig. 6). An exposed silver halide sheet 179 is fed in at E and a plain paper sheet 188 laid on table 187. After passing through developer bath 182, the silver halide sheet engages the leading end of the paper sheet 188 through opening 190 and together they are passed out of the device between roller pair 169, 170, the latter roller being heated. On manually separating the two sheets, soft gelatine is transferred to the paper sheet 188. The sheet 179 is then fed into the device again between rollers 171, 172, through acidifying/oxidising bath 194 and into contact through an opening 201 with an ink transfer sheet 199 laid on the table 200. The sheets 179 and 199 are pressed into contact for effecting transfer of ink by roller pairs 175, 176, and 177, 178, the latter pair being heated. Drive for the feed rollers is transmitted by belt and pulley drive from a motor 161.